Producers and those who utilize voice and/or data communications systems have become very interested in optical fibers as a transmission medium. The advantages of fibers over other kinds of transmission media are well known. The potential bandwidth (or message carrying capacity) of optical fibers is extremely high. Systems using optical cables are resistant to electromagnetic interference which sometimes plagues systems having electrical cables. Moreover, optical cable systems are considered somewhat more secure than electrical cable systems since it is more difficult for unauthorized personnel to tap or access a fiber optic cable without being detected.
Fiber optic devices use single or multiple strands of fibers each having an inner circular glass core coated with a circumferential cladding having a different index of refraction. Light is transmitted along the core and totally reflected from the interface between the core and cladding. Such devices can be used as transmission lines for transmitting information bearing light energy. A transmission line can be formed from a single fiber or it can include a plurality of fibers bundled together as a cable. Additionally, several transmission lines can be arranged in parallel for the simultaneous transmission of information along each of the separate lines.
Where the transmission line is relatively long and extends between different pieces of apparatus, the transmission line is divided into segments and the different segments are connected to each other using separable fiber optic connectors which have been developed to meet this need. The principal design criteria of such connectors is to connect the transmission lines in an end-to-end relationship in such a manner as to minimize the loss of light energy as light traverses from one end of one line into the end of the adjacent segment of that line. The most efficient transfer of energy occurs when the axis of the two lines are in precise alignment. In other words, if the ends of the lines are out of alignment either due to lateral or slight angular displacement, light energy will be lost. Thus, most fiber optic connectors are designed to bring the ends of the transmission lines into as perfect an axial alignment as possible.
When a transmission line is made up of a plurality of individual fibers joined together to form a bundle or cable for the transmission of a single piece of information along the line, it is not critical or necessary that the individual fibers be aligned exactly with the ends of the fibers on the other cable since most of the light emitting from one end will be accepted into the fibers on the other side. However, where a transmission line is made up of a single individual fiber, it is more critical that the end of one be perfectly aligned with the end of the other to minimize energy loss.
There presently exist various connector assemblies in the art which are capable of attaining such precisioned, end-to-end alignment, once the selected individual fiber optic connectors (each having at least one optical fiber therein) are positioned within a designated common housing (or housings) of the assembly. Due to manufacturing tolerances, however, proper alignment between these individual connectors and common housing (also referred to in the art as an adapter) is often difficult, particularly when attempting to align and position paired arrangements of such individual connectors. To accomplish this, such individual fiber optic connectors have been encased within a singular housing, being referred to in the art as a duplex connector, and then inserted within the corresponding, common housing. Separation of these individual connectors (typically two) in such a substantially fixed arrangement is, obviously, very difficult. Because of this relatively rigid form of encasement, flexibility of movement between the ends of these individual connectors is substantially prohibited, thus complicating final alignment and positioning of the connectors within the designated common housing.
As will be defined herein, the instant invention provides what can also be referred to as a duplex connector, but one wherein originally separate, individual fiber optic connectors are retained in not only a side-by-side orientation capable of being inserted within a corresponding common housing (to form a connector assembly) but also an orientation which permits relative freedom of movement between said individual connectors so as to accommodate for manufacturing tolerances in the common housing and/or housings of the individual connectors, thereby facilitating such alignment.
It is believed that such an invention would constitute a significant advancement in the art.